a certain doorway

There is a certain Doorway through which some have crossed over to other places, other dimensions, from which few if any ever return. Some say the Doorway is a Painting, a Magic Painting. Others say it is a device---a stargate, a portal, a magic casement---created by unknown and unknowable beings from the singularity at the very heart of the Cosmos. Mathematicians believe it is a flaw in the